Disk-Based Mechanisms

DRBD is an open-source Linux-based disk replication mechanism that works at the individual write level to replicate writes on multiple machines. Although not directly supported by major
database vendors (at the time of writing of this document), it provides a way to inexpensively configure redundant distributed disk for disk-consistent databases (such as MySQL, PostgreSQL, and
Oracle). For information, see http://drbd.linbit.com.